At the end of the last summer vacation of high school, Youta Narukami spends his days preparing for the university entrance exams, when a young girl named Hina suddenly appears, proclaiming herself as the "god of omniscience." Youta is confused and does not believe Hina when she tells him "The world will end in 30 days." After witnessing Hina’s God-like predictive ability, Youta begins to believe her powers are real. Hina, who is innocent and childlike despite her supernatural powers, decides for some reason to stay at Youta’s home. Thus begins the start of their lively summer before the end of the world.
In her Junior High years, the pitcher Yomi Takeda was not able to get very far in a cross-school baseball tournament. Since the catcher on her team wasn't at her level, she couldn't use her signature move, the "Magic Throw," and eventually regretted not being able to use it. After Junior High, she decided to stop playing baseball and went to Shin Koshigaya High School, a school without a baseball club. There, she found her long lost childhood friend, Tamaki Yamazaki, who used to play catchball with her when they were kids. Tamaki also played baseball during her Junior High years as a catcher, and could even catch Yomi's "Magic Throw!" Their promise with each other during their childhood could now be fulfilled! Walking together on the road of baseball once again... The story of the girls who love baseball will begin!
One day, Mitsuha falls off a cliff and is transported to a medieval Europe–type world! After a near-death encounter with a pack of wolves, she then realizes that she's able to transport between two worlds—this one and her own. Taking advantage of this ability, Mitsuha decides to live in both worlds and calculates that she'll need 80,000 gold coins to be able to retire! Mitsuha now has to come up with different ways to collect her gold coins!